How to use the sales tax calculator
Use "Add tax" when you know the price before tax and want the final total. Use "Remove tax" when you have a tax-inclusive total (like a receipt) and want the original pre-tax price and how much of it was tax. Enter the amount and your local rate.
The formulas
Add tax: Total = Price × (1 + rate) · Remove tax: Pre-tax = Total ÷ (1 + rate)
Here "rate" is the percentage as a decimal — 8% = 0.08.
Worked example
- Add: $50 at 8% → tax $50 × 0.08 = $4, total $54.
- Remove: a $54 receipt at 8% → pre-tax $54 ÷ 1.08 = $50, of which $4 was tax.
Sales tax, VAT, and GST
The math is identical — they're all consumption taxes added to a price. Only the names and rules differ: the US uses sales tax (set by state and city), much of Europe uses VAT, and countries like Australia, Canada, and India use GST. Always enter the exact rate that applies.
Common mistakes to avoid
Subtracting the tax percentage from the total to "remove" tax — that's wrong; you must divide by (1 + rate). Using the wrong local rate. Forgetting that some items (like groceries) may be taxed at a different rate or exempt.
Frequently asked questions
What is 8% tax on $50?
$4, making the total $54.
How do I get the pre-tax price from a total?
Divide the total by 1 plus the rate as a decimal. $54 ÷ 1.08 = $50.
What's the difference between sales tax, VAT, and GST?
Same math, different names and rules by country.
Why do rates vary?
They're set by country, state, and sometimes city, and can differ by product type.
What does tax-inclusive mean?
The price already contains the tax. Use Remove tax to split it back out.
Is my data saved?
No. Everything runs in your browser; nothing is uploaded.